The present invention relates to the field of coolant-fed tools, such as the kind used in a tool assembly. More specifically, the present invention is an apparatus for preventing fluid from flowing around a tool secured to a tool holder by a combination of a collet and a collet nut such that the coolant is forced down an inner chamber of the tool to provide both a coolant and a lubricant at the tool tip.
Coolant-fed tools, such as the kind used in a drill press, are commonly used to drill or bore holes into extremely strong materials, such as steel or brass. Coolant-fed drills includes a tool which has an inner chamber through which pressurized coolant is fed to provide both a coolant and a lubricant at the tool tip. The pressurized fluid both flushes out shavings of the material being drilled and prevents the tool bit from overheating and breaking.
In most instances, it is important to maintain a strong fluid pressure within the inner chamber of the tool and at the tool tip. In some applications, it is necessary to have a fluid pressure of greater than 200 pounds per square inch (psi), and in some applications it is necessary to have a fluid pressure of up to 1,500 psi. In order to provide such a strong fluid pressure, it is necessary for all of the fluid to be forced within the inner chamber of the tool. Fluid flowing around the tool can diminish the pressure and a tool break-down can occur.
In most machining applications, fluid from a pressurized fluid system is flooded toward the end of the tool opposite the tool tip. Some of the fluid is forced down the inner chamber of the tool. However, a substantial portion of the fluid travels around the tool and through slots in a collet securing the tool to the tool holder. These slots are necessary to allow the collet to collapse and securely grip varying sized tools.
Due to the configuration of most coolant-fed tool holders, a substantial amount of pressure is lost when fluid travels around the drill bit through the slots and the collet. Therefore, there is a need for an apparatus which can be adapted to standard coolant-fed tool holders which will prevent pressurized fluid from flowing around a tool, and will thus force all fluid down the inner chamber of the tool to maximize pressure at the tool tip.